The most important and difficult part of the work of the surgeon is to perform anastomoses of hollow anatomical structures. At the end of the twentieth century, most of the surgical anastomoses are still performed in same way as hundred years ago--by manual suturing.
Blood vessels are anastomosed by multiple manually placed stitches. The surgical procedure is time consuming and demands highly specialized skills. This is associated with a substantial rate of complications due to ischemia in the tissues suffering from the interrupted blood supply during the procedure. Bleeding frequently occurs from the suture lines. Unevacuated blood clots and the persistent drainages increase the chances for development of infections. Subjective technical mistakes by the surgeon can result in stenosis or thrombosis of the anastomosis.
Anastomoses of gastrointestinal organs have been automated to some extent by circular staplers. In brief, their method of operation is: first, an anvil and a stapling cartridge are introduced inside the ends of two hollow organs through a side slit of one of them; second, the ends of the two organs are inverted between the stapling cartridge and the anvil by two manual sutures; and third, multiple staples are ejected axially from the cartridge, they pierce the inverted walls of the two organs and are clinched by the anvil.
Circular staples have proven to be perform more reliable anastomoses as compared to these accomplished by manual stitches. Still, their benefit is outweighed by several drawbacks. First, the time needed to complete the anastomosis is not actually reduced as the surgeon has to place two manual sutures to invert the ends of the two organs and after that has to suture manually the incisional slit. Second, the higher risk of technical failure associated with the process of manual suturing remains present as the surgeon has to close the incisional slit by multiple hand stitches. And third, the application of circular staples is limited only to relatively large organs, such as the intestines and the stomach.
It is evident, that development of devices and methods for quick, easy, and reliable anastomoses of hollow anatomical structures is extremely important for reducing the complications and improving the outcome in many surgical procedures, especially in cardiovascular surgery.
Various stapling devices have been proposed for implementation with blood vessels. Most of them are based on a similar method of operation as that of circular staplers--to suture the ends of blood vessels by axially ejected staples. The walls of blood vessels cannot be inverted (as the walls of gastrointestinal organs) because this will impede the blood flow. For that reason, blood vessels are either everted or cuffed before being stapled by the proposed stapling devices. Everting or cuffing body organs is more difficult and time consuming to perform than inverting. This is particularly true for blood vessels, which in general are located in less accessible places and have more rigid walls than intestines. Sometimes, this is even impossible to perform sometimes when the vessels are with substantially rigid walls (such as arteries with atherosclerotic changes). For these reasons, none of these stapling devices for blood vessels has established a practical application.
A device for accomplishing anastomoses of blood vessels, without changing their natural configurations, by ejecting staples in radial direction, is described by Perouse (U.S. Pat. No. 5,346,115). The described device has several important limitations. It can be used only for attachment of a non-rigid graft to the internal surface of a blood vessel. The internally attached graft narrows the lumen of the vessel. This limits the application of the device only to relatively large vessels. Direct anastomosis (without a graft) of two blood vessels cannot be accomplished. The device can be used only for end-to-end anastomosis. Side-to-end anastomosis cannot be performed.
A side-to-end vascular staple apparatus and method of stapling is described by Kaster et al. in U.S. Pat. No. 5,234,447, in U.S. Pat. No. 5,366,452, and in U.S. Pat. No. 5,403,333. In the described method, one of the vessels is inserted through a mandrel and cuffed over the end of the mandrel. The procedure can be performed only if the other end of the vessel is loose, as the mandrel has to be withdrawn back after the completion of the procedure. Therefore, the staple apparatus can be used to anastomose only the first end of a vessel graft. It cannot be used to anastomose the second end of the graft because the mandrel cannot be withdrawn after the first end is joined. This is a major practical limitation of the described apparatus and method. Furthermore, the diameter of the staple apparatus, after the interior engagement members are bent, is larger than the diameter of the side opening. This makes difficult the insertion of the staple apparatus into the vessel. Deforming the internal engagement members consequently one by one slows additionally the anastomosing procedure. And finally, the end anastomosed vessel needs to be cuffed in order to perform the procedure. As explained above, this is an important limitation for the practical application of the described apparatus and method.
Many authors have proposed various types of rigid connectors for performing quick anastomoses of hollow organs. While the connectors differ much in structures and forms, their method of operation is principally the same. Two hollow body organs become joined by compressing their flanged (everted or inverted) or cuffed walls between the rigid surfaces of two coupled connectors.
Compressing body organs between rigid connectors is associated with a very high risk of serious complication. Applying a constant pressure on a substantially large area of body tissues produces adverse changes in the tissues. The compressed tissues suffer ischemic changes due to the decreased blood-oxygen supply. A high pressure deprives the tissues from blood-oxygen supply. This results in a necrosis, which may lead to rupture of the anastomosed organs. A moderate pressure diminishes the blood-oxygen supply. This slows the metabolism and the regeneration of the tissues. The compressed tissues become thinner while their healing is impeded. This may lead to a leak of the anastomosis before the tissues are healed. On the other hand, applying a light pressure may be inadequate to join the organs in a fluid tight manner, which can manifest with an immediate leak of the anastomosis.
Because of the significant risk of serious complications, none of these rigid connectors has found practical utilization. In addition, the walls of at least one of the two anastomosed organs must be flanged or cuffed. As it was explained above, this alone is a major limitation for the practical application of the connectors.
The present invention solves all these problems. It provides a new connector and methods for attaching the connector to hollow anatomical structures in an easy, fast, and reliable manner, which is overall superior to the currently used devices and methods for anastomosing and to these known of the prior art. The new connector has a very universal application. It can be used to perform end-to-end or end-to-side anastomoses of different anatomical structures. It can be used for anastomoses of hollow body organs, for bypass and shunt procedures, for implantation of hollow artificial devices, for organ transplants, for intestinal stomas, and for other surgical procedures.